Al Jean has the placid and pensive countenance of a man deep in creative thought.

But if you want to see “The Simpsons” executive producer and writer’s face light up, all you have to do is mention his hometown of Farmington Hills. That’s where he grew up and attended Harrison High School and where his family’s business, Jean’s Hardware, catered to customers’ DIY needs for 50-plus years until the doors closed for good in April of last year.

“The sad thing is, it’s a particularly Detroit story, but also a national story when you have a mom-and-pop store and a corporation opens a nearby Sears, or Home Depot or Barnes & Noble and people start shopping at those,” Jean, 55, said of the hardware his grandfather founded in 1963, which started out as a gas station and feed store.

His dad ran the store for his grandfather and when he retired, his aunt and uncle, Pat and Hank Yeomans, became the owners. Even though Jean’s Hardware is closed, it lives on via a Facebook fan page.

“It’s very hard to start your own business and maintain it,” said the husband and father, who worked in the store as a teenager before leaving for Harvard, where he graduated with a degree in math. “I’m grateful that we had 50 years and that people loved it. I’m very nostalgic. I still have a picture of it and a part of me never believed it would ever close.”

Jean said he’s paying homage to the store in an upcoming episode or two of “The Simpsons” with jokes about corporate Goliaths. “The Simpsons” is TV’s longest-running scripted series and is in its 28th season. The 600th episode, which also happened to be the 27th “Treehouse of Horror” installment, aired Sunday.

“I never thought ‘The Simpsons’ would still be going, but here we are and it’s exciting,” Jean said with a chuckle.

The latest ‘Treehouse of Horror’ included a drought version of ‘The Hunger Games’ and a James Bond/‘Kingsman’ rift. Sarah Silverman’s in it, and Drew Carey and Donald Fagen from Steely Dan also lent their voices.

Jean said he’s also looking forward to an hourlong episode of “The Simpsons” slated for January, which is a hip-hop version of “The Great Gatsby.” Taraji P. Henson of “Empire” will guest star, as will Detroit native Keegan-Michael Key, formerly of “Key & Peele.”

After season four of “The Simpsons,” Jean and then co-executive producer Mike Reiss, left the show to create the short-lived series “The Critic” (1994-95) and “Teen Angel” (1997-98). Jean returned to “The Simpsons” in 1998 and three years later, became the showrunner for season 13. Jean has been the showrunner and head writer ever since.

Matt Selman, who also is a writer and executive producer on “The Simpsons,” said Jean is a calm and tireless jokester.

“Al is the best. I’ve never seen him lose his temper in the nearly 20 years I’ve worked with him,” Selman said. “And he’s so funny. He never rests, always wants to be better and never stops pitching. Legend has it, when the show first started, they were working around the clock to make the show a hit. Al briefly dozed off in the writer’s room, woke up and pitched a joke. From sleep to joke just like that. That’s Al.”

Over the years, Jean has snuck in a few Detroit references and jokes on “The Simpsons.” He even made Ned Flanders a Detroit Lions fan. Although he’s lived in Los Angeles for more than three decades, Metro Detroit will always be home.

“When I went home in 2012, I took my daughter to my high school — she’s 11 now — and showed her all the championship trophies and everything,” Jean said, adding that he’s glad he did so while he could. Harrison High School is slated to close in 2019 because of Farmington Hills’ shrinking student population.

“I remember Harrison High School being built,” Jean said, setting up his punch line. “Maybe I’m the problem. That would make a perfect ‘Simpsons’ joke.”